Electrical leads and electrodes are commonly utilised in the medical field for applications such as stimulation, sensing, ablation and defibrillation.
Traditionally, medical electrodes comprise machined metal or coiled metal wire components which, while suitably conductive, do not provide the flexibility in both design and mechanical properties afforded by a metal coated polymer. Furthermore, metal coated polymers are particularly suitable for use in larger area electrodes where their light weight, flexibility and versatility are key advantages.
The use of metal coated or metal filled polymers as medical electrodes has been considered. For example, in U.S. Pat. No. 5,279,781, a metal filled fibre for use as a defibrillation electrode is described. The metal in this case is added during the spinning process. To render the electrode suitably conductive, however, requires the addition of a significant proportion of metal to the fibre which in turn has an adverse effect on the mechanical strength of the electrode.
Further structures, including metal filled silicones and intrinsically conductive polymers, have been considered for use as medical electrodes although it has been found that such structures do not have the required level of conductivity necessary for the abovementioned medical applications.
Typically, the problem encountered with using a polymeric material as an electrode is that it is difficult to obtain a good electrical connection to the electrode. In U.S. Pat. No. 5,609,622, an electrical connection was achieved by utilising an electrode having metal wires embedded in its wall. The electrode was then subjected to an ion beam treatment with metal such that the metal was deposited within the wall and therefore contacted the wires. In this case, however, the electrical connection was only shown to occur at one end of the electrode and further, it is questionable whether a good connection is achieved by this method as it relies upon the incidence of metal contacting wire through the thickness of the plastic.
The present invention provides an electrical lead and/or electrode which overcomes the problems of the prior art.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.